I'll share my password system again, as it also can be used for cases like this where you want to let someone else know your password, but still keep it unusable for anyone who gets that info.
I have a list of logins and passwords on paper in plain view, and on the computer. But, they aren't the real passwords. They are just a small portion of the password. They are added to two 'keywords' that I have memorized (easy, as I use them often). For example, say you chose the 'keywords' "APPLE123", and "zebra789" (but don't use actual words, those are weaker). The written password for my local bank is "L$B", so the actual password is APPLE123L$Bzebra789".
All you need to do is to share those keywords with them ahead of time, and don't write them down where you keep your passwords. Limit the keywords to alpha-numeric, and add any special character requirements to the unique written portion, that assures your keywords will be accepted at all systems (which might reject certain special chars).